Clothes drier



Oct. 30, 1962 Filed Aug. 7, 1959 R- A. FLORA ETAL CLOTHES DRIER 6Sheets-Sheet l 000/1779 air Dry/77g air a4 38 K /36 90881 I00 24 i 0 74ii-.. 4. l

70 I 68 9e e4 l 82 9a 30 loo INVENTORS 7716/! Attorney Fig. l

Oct 1962 R. A. FLORA ETAL 7 3,050,593

CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 2 INVENTORS Y Raymond A.Flora George. A. Nay/muse Jack W Savage Ralph K. Shewmon The/r Af/omeyOct. 30, 1962 R. A. FLORA ETAL 3,060,593

CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 3 INVE/V TORS Raymond A.Flora George- ';4: Nay/rouse Jack W. Savag'e 4 Ralph .Slwwmon T/reirAfro/nay Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

CLOTHES DRIER Filed Aug. '7, 1959 6 Sheets-Sheet 4 INVENTOR-S Fly, 5Raymond A. Flora c j George/1. Nay/louse Jack mavage Drying BY Ralph KSkew/non Their florney Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 5 INVENTORS 6 Raymond A.F/ora'= George A; Nay/muse Jack W. Savage Ra/p/l K. Shaw/nan TheirAl/omey Oct. 30, 1962 R. A. FLORA ETAL 3,060,593

- CLOTHES DRIER Filed Aug. 7, 1959 6 Sheets-Sheet 6 'l/VVE/VTO/PSRaymond A. Flora George A. Neyhouse Jack W. Savage Ralph K. Siren/man IBY 7 The/r A fforney .nie

3,i 50,593 Patented Oct. 30, 1962 3,060,593 CLOTHES DRIER Raymond A.Flora, George A. Neyhouse, and Jack W. Savage, Dayton, and Ralph K.Showman, Centerville, Ohio, assignors to General Motors Corporation, De-

troit, Mich, a corporation of Delaware Filed Aug. 7, 1959, Ser. No.832,186 12 Claims. (Cl. 34-433) This invention relates to a domesticappliance and more particularly to an improved drying apparatus.

A major consideration of the appliance industry con cerns the reductionin product size and the standardization of parts. In the manufacture ofdrying apparatus, the prime moving and air circulating system for thedryer constitutes a severe obstacle to this reduction in size. In thepast, it has been disposed primarily in a space beneath the tumblingdrum of the drier and has, thus, added to the size of the drier.Further, prior art devices have used belt and pulley systems to transmitpower for rotating the tumbling drum and for circulating air through thetumbling drum. This, too, is a space consuming arrange ment. Therefore,these practices and other problems are overcome by this invention in amanner to reduce the over-all size of a clothes drier and to provide acompact prime moving and air circulating system which may beinterchangeably adapted to difierent driers.

Accordingly, it is an object of this invention to provide a clothesdrier with a prime moving system which mounts in a central portion ofthe tumbling drum.

It is also an object of this invention to provide a clothes drier whicheliminates the need for belts and pulleys in its prime moving system.

A further object of this invention is the provision of a motor for aclothes drier which rotates the tumbling drum from one end of the motorand the air impelling means from the other end thereof.

It is also an object of this invention to provide a prime moving and aircirculating system which may be used interchangeably for difierent typedriers.

A more specific object of this invention is the provision of an integralunit for a clothes drier which includes a tumbling drum driving means,an impeller driving means and a heater in one compact unit.

Another object of this invention is the provision of a compact unitaryprime moving and air circulating system for a forced draft drying systemand an induced draft drying system.

A further object of this invention as it applies to a forced draftdrying system is the provision of air flow passageways through the motorwhich are connected to a blower and tumbling drum whereby the motor iscooled by air which then commingles with the drying air to add the motorheat to the heat of drying.

Another object of this invention is the provision of an impeller for amotor driven clothes drier which circulates predetermined pro-ratedquantities of drying air through said drier and cooling air through saidmotor.

A more specific object of this invention is the provision of a ductsystem for a prime moving and heated air circulating system whichprovides an insulating air barrier between the heater for said air andthe motor of said prime moving system.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein preferred embodiment of the present invention areclearly shown.

In the drawings:

FIGURE 1 is a schematic side sectional view of a drier provided with theprime moving and forced draft system of this invention;

FIGURE 2 is a fragmentary elevational view with parts broken away toshow the clothes drying air and motor cooling air housing in accordancewith the forced draft form of this invention;

FIGURE 3 is a fragmentary sectional view of the prime moving and aircirculating system shown in FIGURE 1;

FIGURE 4 is a fragmentary sectional view of the means for mounting atumbling drum to the prime moving system of this invention;

FIGURE 5 is a schematic sectional view of a clothes drier provided witha second embodiment of this invention showing an induced draft aircirculating system;

FIGURE 6 is a rear elevational view of the FIGURE 5 drier with partsbroken away to show the combined motor cooling and clothes drying airfiow duct system of this second embodiment; and

FIGURE 7 is a fragmentary sectional view of the prime 7 moving and aircirculating system shown in the induced draft arrangement of FIGURE 5.

In accordance with this invention and with reference to FIGURE 1, aforced draft drying system is set forth for a clothes drying apparatus.A clothes drier Iii is shown which is provided with a rear drum supportbulkhead 12, a base portion 14, and a front wall 16. A top panel 18 isincluded to cover the drier 10 and provide the housing means whereby acontrol 20 is positioned for any conventional control of the clothesdrier. Within the clothes drier 10 is located a tumbling drum 22 whichhas a rear wall 24 and a front annular closure-26. The annular closure26 defines a collar 28 which forms an access opening into the tumblingdrum 22. The opening 28 is also the means of egress for air circulatingthrough the tumbling drum 22. For admitting air to the tumbling drum,the rear wall 24- includes a plurality of ports 30 which connect with aninlet air flow space or annular heated air chamber 32 between the rearwall 24 of the tumbling drum and the rear support bulkhead 12. Anannular seal 34 defines the outer limits of the annular air space 32 andis mounted on the support wall or bulkhead 12 and adapted to seal in arelative rotational fashion against a shoulder 36 at the rear of thetumbling drum 22.

The front wall 16 has an inwardly turned shoulder portion 40 whichsupports a front port plate 42 having a cylindrical inlet collar orsupport flange '44 which nests within the drum collar 28 and is adaptedto support the drum on a plurality of nylon rubbing blocks (not shown)interposed between the collars 44 and 28. Between the support blocks, astrip of felt sealing material 46 isutilized to prevent leakage from theair flow system. An open ing 48, formed by the shoulder 40 in the frontwall 16, isclosed by a door 50- in which a plurality of louvers 52 arestamped to provide for egress of air from the tu'mblingdrum 22. Anysuitable seal 49 may be used to minimize air leakage when the drieris'in operation.

The door 50 has a rear panel 54 on which alint collecting housing 56 isaflixed. The housing 56 has a ported rear panel 58 which receives airfrom the tumbling drum 22. When the door 50 is in closed position asseen in FIGURE 1, an annular seal 60 serves to prevent air from escapingaround the edges of the lint collecting housing 56. Within the housing56, a lint screen 62 is disposed which has a support and removablehandle portion 64 which permits removal of the lint screen for cleaningwhen the door 50 is opened.

The foregoing general construction of a cabinet and drum for a dryingapparatus forms'no part of this inven' tion. Thus, to constitute anoperable device, there remains to be had only a prime moving systemwhereby the tumbling drum 22 may be rotated and a flow or current ofheated air caused to proceed through the tumbling drum in a clothesdrying operation. In the past, this has been accomplished by a motorlocated in the bottom of the drier and arranged with belts and pulleysto drive the tumbling drum 22 and an air circulating means or blower.The drier of FIGURE 1 is shown with a space 66 beneath the tumbling drum22 to indicate the waste area which has been occasioned by prior artdesigns. It is the pur pose of this invention to save this space 66 in amanner to reduce the over-all dimensions of the drier 10 or to free thespace 66 for use in another manner.

A compact prime moving and air circulating system 68 is shown generallyin FIGURE 1. The system includes a motor 70 having a full speed impellershaft portion 72 and a reduced speed drum shaft portion 74. To achievethese ends, the motor 70 includes a planetary gear speed reductionsegment shown generally at 76. The rear wall 24 of the tumbling drum 22includes a dished out or inwardly recessed portion 78 which receives thegear reduction housing 76 and a motor mounting housing 80'. It is notnecessary that the drum wall be recessed at 78, however, in order tofully avail oneself of the advantages of compactness in this invention,it is desirable to dispose the prime moving system 68 within an areawhich is otherwise waste space within the tumbling drum. The primemoving and air circulating system 68 includes an impeller showngenerally at 82 having a first or motor cooling air stage 84 and asecond or drying air circulating stage 86. The impeller 82 is attachedin any suitable fashion to the motor full speed shaft portion 72 as by aset screw 83 in a keyway. A heater housing 88 provides the means forcovering the heaters 90' and includes inlet openings 92 which directsair from the atmosphere to the impeller 82.

Problems in heat radiation occur with the heaters 90 as close to themotor 70 as seen in FIGURE 1. This invention provides an air barrier 94interposed between the heaters 90 and the motor 70 as will be explainedmore fully hereinafter.

In accordance with this invention, the prime moving and air circulatingsystem 68 is adapted to be applied to any drier having a forced draftair flow and a means of support adjacent the tumbling drum. Inparticular, the motor mounting housing '80 is carried by a support oradapter plate 98 which is spaced from the rear bulkhead by a pluralityof spacers 100. However, it should be recognized that the motor mountinghousing 80 could be mounted directly on the rear bulkhead 12 of thedrier 10. In such a situation, duct work could be provided to connectthe ported rear wall 24 of the tumbling drum to the outlet of the blowerimpeller 82.

The explanation of the air flow system of this invention is facilitatedby using solid-line arrows to indicate a clothes drying air flow anddashed-line arrows to indicate a motor cooling air flow. Thus, withreference to FIGURE 1, the drying air flow is created when the motor 70is energized to rotate the shaft portion 72 and the impeller 82 thereon.Outside air is drawn through the heater housing '88 by way of inlets 92.This air is heated by the heaters 90 and is forced by the impeller stage86 into the annular space 32 adjacent the rear wall of the tumblingdrum. From this point, the heated air is forced through the perforations30 in the tumbling drum and through the tumbling drum 22 to the outletcollar 28. From this point, the air, which is then moisture-laden, isforced through the lint collecting screen 62 and through the louveredaccess door 50. At the same time, the motor 70 is cooled by an airflowtraversing a path shown in dashed arrows. To do so, the intake duct 96is caused to direct cool outside air to the motor 70 by the suctioncreated by the first stage 84 of the impeller 82. This motor cooling airwhich is heated by the operation of the motor 70 then mixes with the airdrawn over the heaters 90 and together the combined flows proceed toevaporate moisture from fabric in the tumbling drum. It should thus beseen that the novel air circulating system of this invention not onlycools a motor situated in a high temperature area but serves also toutilize the heat of the motor in speeding the drying of the fabricplaced within the tumbling drum 22.

The details of the novel prime moving and air circulating system of thisinvention will now be set forth in connection with FIGURES 2 and 3. Themotor 70 is provided with an outer casing 110 in which a plurality ofcircumferentially arranged air cooling ports 112 is formed. This casing114) is spaced from the motor mounting to form an annular motor coolingair passageway 115. A segmented or interrupted tenon 114 provides theinterchange of air through one end of the motor housing and thepassageway 115. Similarly, an end frame 116 at the opposite end of themotor 70 is provided with end frame openings 118 to permit the axialflow of air into the motor housing 110. The motor 7t) is a conventionalinduction type and includes a stator 120 and a rotor 122 disposed withinthe stator. A motor speed of 1725 rpm. has been found satisfactory forthis invention. The rotor 122 is formed with a plurality of axiallydirected air passageways 124 which permit the through-flow of air fromthe end frame openings 118 to the air cooling outlet openings 112 and114. Attached to the rotor 122 of the motor 70 is a motor shaft 121which has a keyway portion 122 for lockingly receiving the impeller 82.The opposite end of the motor shaft 121 is formed with gear teeth 125which act as the driving pinion for the speed reduction gearing unit 76to effect a rotation of the shaft 74 at approximately 50 r.p.m.

Although the reduction gearing per se forms no part of this invention,the speed reduction is accomplished by a planetary gearing arrangementas follows. The shaft gear 125 drives a first planetary gear 126 and asecond planetary gear 127. The planetary gears 126 and 127 revolve onbearing ring portions 128 and 130. In turn, the planetary gears 126 and127 include shank portions 132 and 134, respectively. The shank portions132 and 134 are formed with gear teeth which intermesh with a ring gear136. The planetary gears 126 and 127 rotate about spirally grooved pinswhich rotate the driven gear or output shaft 74 as the planetary gearsrevolve. In this arrangement, it is possible to achieve an impellerspeed of 1725 rpm. (the synchronous speed of the motor) and an outputshaft speed of 50 rpm. (the reduced output speed of the gear reductionunit 76). Suitable oil seals 137 are mounted about the input and outputshafts of the speed reduction unit to retain an oil bath therein.

The manner in which the drum 22 is attached to the prime moving systemis seen in FIGURES 3 and 4. To attach the prime moving system to thetumbling drum 22, a nut 142 may be utilized. The output shaft 74 isformed with a flat 144 which matches a similar fiat in a reinforcementportion 146 which is secured to the inward recess 73 of the tumblingdrum. The bolt 142 is threaded into the end of the output shaft 74 andthe drum is thereby rigidly afiixed to the prime moving system 68. Asaforesaid, the entire prime moving and air circulating system 68 isaffixed to a support bulkhead, such as 12. The bulkhead thus becomes themeans for supporting the rear end of the tumbling drum.

The heater housing 88 will be described more fully with reference toFIGURE 2. The housing 88 is formed with a flange 159 which may befastened as at 152 to the rear bulk-head 1-2. The housing 88 is formedwith openings 92 which lie adjacent the heaters 90. Extending from agenerally central portion of the housing 88 is a motor air intake duct96 which is generally cylindrical in shape. Circumscribing the duct 96is an annular passage 94 which forms a thermal insulating barrier toprotect the motor 70. To form the insulating barrier or passageway 94,the housing 88 has an inwardly turned cylindrical wall portion 154 whichis reverse-bent to the cylindrical air intake duct 96. At the inwardlydirected end of the wall portion 154 are a plurality ofcircumferentially arranged, generally circular insulating barrier airoutlet openings 156. These openings 156 communicate with the inlet sideof the second stage 86 of the impeller 82. Thus, when the impeller 82 isrotating, air is drawn through the passageway 94 and the openings 156 tothe inlet side of the impeller stage 86. Since the heaters are on oneside of the housing wall 154 and the motor 70 is disposed only a shortdistance therefrom, the cylindrical or annular passageway 94 provides abarrier or cool air during operation of the drier. This barriereffectively insulates the heat of the drier heaters 90 from the motor7t) and, thus, enhances a long life of trouble-free operation for theapparatus.

The housing 83 is designed to form a heating chamber 39 in which theheaters 96 are disposed. To admit the heated air to the inlet side ofthe impeller stage 86, the rear bulkhead 12 has an opening 158. Thisararngement permits cool air to enter the heater chamber 89 by way ofinlet openings 92 and heated air to leave the housing through bulkheadopening 158 to the inlet side of the impeller stage 86.

The impeller 82 is formed with a back plate 160' in which a plurality ofopenings 162 are formed to permit air flow to the motor 70. The impellerincludes a cylindrical bafile portion 164 which lies in closely adjacentspaced relationship to the intake duct 96 and the motor end frame 116.In this manner, motor cooling air flow entering duct 96 is substantiallyprevented from bypassing the motor 76. Extending from the baffle portion164 is a radially outer extension 166 of the back plate 16%. The backplate extension 166 supports the first impeller stage 86 as well as thesecond impeller stage 84, thereby transmitting motor shaft rotation tothe impeller. The plurality of impeller blades 84 and 86 are suportedrespectively at their axially outer edges by an annular support ring 168and 174). It should be obvious that the impeller 82 could be formed witha single back plate, consolidating portions 16d and 166, by redesigningthe housing 83 to permit the impeller stages to move rearwardly. Theconfiguration shown in FIG- URE 3, however, lends itself to a compactarrangement requiring a minimum of drier cabinet space.

The foregoing structure divides the air circulating system into threeair flow paths as follows. The drying air flow derives its source of airfrom the atmosphere from which point the air proceeds through theopenings 92 in the heater housing. After being warmed by the heaters 90,the heated air leaves the housing 88 by way of bulkhead opening 158 andenters the inlet side of the first stage 86 of the impeller 82. Theimpeller stage 86 draws the air from the heater housing and throws itradially outwardly into the annular space 32 adjacent the rear wall ofthe tumbling drum 22. From this point, the air may proceed through thetumbling drum in a conventional manner, picking up moisture from thedampened clothes therein.

With the motor 70 disposed in such close relation- I ship to the heaters90, it is necessary to provide a means for cooling the motor. For thispurpose, a second air flow is required-a motor cooling air flow. Themotor cooling air proceeds also from the atmosphere through a motor airintake duct 96. Since the duct 96 is in line with the openings 162 inthe impeller back plate 160, the cooling air flow may enter the motor'70 through openings 118 in the motor end frame 16. The rotor 122includes the passageways 124 through which the cooling air proceeds tothe outlet end of the motor 70, namely, the circumferentially arrangedseries of ports 112 and the segmented tenon 1 14. As the cooling airleaves the motor, having picked up the heat therefrom, the air entersthe surrounding cooling air passageway 115 which surrounds the motorcasing 11%. This passageway 115 connect through an opening 117 in theadapter plate 98 to the inlet side of the impeller second stage 84. Theimpeller second stage also connects with the annular space 32 adjacentthe rear wall of the tumbling drum.

A third air flow channel is utilized in this invention to provide aninsulating barrier between the heaters 90 and the motor '70. Theinsulator barrier passageway 24 is opened to the atmosphere and receivesair therefrom whenever the impeller first stage 86 is in operation. Therelatively cool atmospheric air is drawn through the cylindrical orannular passageway 94 and the openings 156 at one end thereof to theinlet side of the impeller stage 86. This insulating air is warmed as itproceeds along the wall 154 of the heater housing 88. The air joins theheated drying air proceeding from the housing 88 by way of opening 158and is thrown into the annular space 32. It will be noticed that allthree air flows commingle or mix at the outlet of the impeller 82. Inthis way, the efficiency of the drier is improved in the fact that theheat loss of the motor is added to the heated air being used to dry theclothes. This novel three-flow air pass has been found to maintain themotor 719 in an exceptionally cool operating condition in spite of itsproximity to the heaters 96 and its generally confined location withinthe drying apparatus.

The foregoing embodiment is adapted to a pusher type or forced draftsystem wherein the air flow is pushed through the tumbling drum.However, certain drier manufacturers prefer the induced draft air flowsystem wherein air is pulled or sucked through the tumbling drum. Thenovel combination prime moving and air circulating system of thisinvention may be equally well adapted to the induced draft system inaccordance with the concepts of this invention as described nextfollowing.

Reference may now be had to the FIGURES 5, 6 and 7 for a completedescription of the induced draft type dried adapted for use with thisinvention. Reference numerals for identical parts in both the forceddraft and induced draft arrangements Will be the same. An induced draftdrier 260 is provided with a front wall 202 having an access opening 204closed by an imperforate door 206-. A support bulkhead 268 is interposedbetween a top wall 210 of the drier and a bottom support 212. Disposedwithin the drier 200 is a tumbling drum 22. As in the first embodiment,a seal 34 may be utilized to provide the or define the outer limits ofan annular space 218 between the bulkhead 208 and the rear wall 24 ofthe tumbling drum. Also as with the first embodiment, a dished out orrecessed wall portion 78 is formed to receive the prime moving systemand induced draft air circulating arrangement shown generally at 224.The tumbling drum 22 has a front access collar 28 which is supported bya front port plate baffle 42 carried by the front wall 202 of the drier.The door 206 carries a perforated bafile 229 which deflects clothingduring the tumbling operation from the area between the tumbling drumand the door 206. The front port plate 42 is formed with a plurality ofarcuately arranged openings 236 which open into a front duct 232.Disposed beneath the front duct 232 is a lint collecting chamber 234 inwhich a lint collector 236 is adapted to be slidably removed by a handle238. The lint collecting housing has an outlet 240 which connects to aconduit 242 leading to a drying air return duct 244 in the aircirculating system.

The prime moving and air circulating system arrangement 224 includes amotor 246, a motor mounting housing 80, a gear reduction housing 76, ablower housing 252 and an impeller 254 rotatably mounted to the motor246 within the blower housing 252. The blower housing 252 has an opening256 which is interconnected with an outlet 258 from the intake or dryingair return duct 244. The motor housing has a flange 260 which may befastened in any suitable manner to an opening 261 in the rear bulkhead268, the housing and the gear reduction extending into the inwardlybulged portion '78 of the tumbling drum.

For heating the air, a heater of any conventional type 262 may bedisposed in a housing 265 adjacent an inlet 264 in the support bulkhead268. Thus, atmospheric air enters the open rear of the drier 200,proceeds through an opening 263 in the heater housing 265 and enters anannular space 266 between the bulkhead and the perforated rear wall 24of the tumbling drum. Air is pulled through the tumbling drum and thefront batllle 229 at which point it enters the front duct 232. Air isfiltered within the lint collecting housing 234 and returns to theintake duct 244. This duct 244 leads to the inlet of the blower 252 fromwhich it is exhausted in any suitable manner to the atmosphere. InFIGURE 5, the drying air flow is shown by a solid arrow, whereas thecooling air flow for the motor 246 is shown in a dashed-line arrow.Reference will now be had to FIGURES 6 and 7 for a detailed descriptionof the combination prime moving and induced draft air circulating systemof this in vention.

The prime mover or motor 246 in the induced draft arrangement isessentially the same as the motor 74} set forth in connection with theforced draft drying system. In the induced draft system, however, themotor casing 110 is designed for air circulation in the followingmanner. At one end of the motor casing, an open end frame 116 includes aseries of radially arranged ports 11% to permit outflow of cooling airfrom the motor 246. At the opposite end of the motor, a series ofcircumferentially arranged ports 112 are arranged in the casing 11ftalong with a segmented tenon 114. The combination of the ports 112 andof the spacing allowed by the segmented tenon 114 permit inflow of airto the motor 246 from a passageway 270 surrounding the motor casing 110within the motor mounting shell 80. Within the motor 246, the rotor 122is provided with a plurality of generally cylindrical passageways 124 toallow the through flow of air in the motor. Thus, cooling air flow isinduced by the impeller 254 to enter the clothes drier cabinet throughan opening 272 in the back of the drier. This air channels in anysuitable manner around the blower 252 and duct 244 in the area betweenthe rear bulkhead 208 and the rear of the drier cabinet and proceedstoward the annular passageway 276 immediately adjacent the motor casing116. The ports 112 in the motor casing as well as the openingsfacilitated by the segmented tenon permit ingress of cooling air to theinternal parts of the motor. Passageways 124 in the rotor guide the airthrough the central part of the motor where the motor heat is entrainedand from which point the heated air is carried from the motor casing byway of outflow ports 118 in the end frame 116. At this point, the motorcooling air enters the blower housing 252 and is expelled or exhaustedfrom the drier.

In this second embodiment, the motor 246 is adapted to support both theupright return duct and the blower housing. The return duct 244 for theclothes drying air lies in juxtaposition to the blower housing 252. Moreparticularly, the blower housing 252 is comprised of a scroll portionwhich terminates in an outlet 274. Fur-. ther, the blower housing has aninner wall 276 and an outer wall 278. The inner wall 276 of the blowerhousing is formed with the opening 256 from which project a plurality ofattachment tabs 282. In juxtaposition to the rear wall 276 of the bloweris the front wall 284 of the return duct 244. Similar, but slightlyshorter, tabs 286 extend from an opening 258 in the duct wall 284. Inthis fashion, the tabs may be aligned in juxtaposition to secure theblower housing 252 to the front duct 244. Further, the outer extensionof the tabs 282 receive one end of a through bolt 290 which serves alsoto assemble the motor 246. A spacer 292 is effective to hold thecombination duct and blower housing in correctly spaced alignment withthe end frame 116 of the motor. It should be noted that the end frame116 is spaced a short distance from the front wall 284 of the systemintake duct 244. In this fashion, the induced draft set up by the inghousing 80 in the second embodiment.

impeller 254 draws motor cooling air satisfactorily through the motor246 as well as clothes drying air from the return air duct 244. However,it is within the purview of this invention to place the end frame of themotor 246 in coplanar relationship with the blower housing opening 256,thereby to draw two completely separated paths of air into theblowernarnely, the cooling air flow through the motor 246 and the dryingair flow from the duct 244 and, more particularly, through the spaces294 interspersed between the tabs Therefore, by regulating the proximityof the motor end frame 116 to the blower opening 256, the amount ofcooling air drawn through the motor may be changed. This is importantfor it permits the system to be adjusted to obtain the proper operatingtemperature for the motor 246. As a practical matter, the spacer 25 2may be lengthened to reduce air flow through the motor and shortened toincrease the air supply.

The motor shaft 121 is adapted to support a hub 296 on the impeller 254.The impeller 254 differs from its counterpart in the first embodiment inthat only a single stage impeller is utilized. Therefore, a back plate293 is fixed to the hub 2% and carries at its outer limits, a pluralityof generally radially directed impeller blades 255. These blades 255 areconnected at their axially inner ends by an annular ring 299. Anysuitable set screw Stltl may be used in conjunction with a fiat on themotor shaft to secure the impeller 254 to the motor shaft 121.

In operation, the motor 246 may be energized in any suitable fashion.Upon energization, the motor will be effective to rotate the impeller254 at the synchronous speed of the motor, generally 1725 rpm. At theopposite end of the motor, the adaptation of the reduction gear unit '76is effective to rotate the tumbling drum at approximately 50 rpm. Airflow will be induced through the tumbling drum 214 by way of the heatingchamber 265. This air will 'be heated at this point by the heaters 262carried through the tumbling drum 22 and the lint filtering arrangementat 234. The return duct 244 will draw the air from the front of thetumbling drum and upwardly toward the blower housing 252. Themoistureladen air will enter the blower housing through the opening 25!;in the front Wall 284 of the duct. The areas between the support tabs282 and 286 provide passageways circumscribing the end frame of themotor 246 whereby the drying air may enter the blower housing 252.Simultaneously, air for cooling the motor will be drawn into the rear ofthe drier around the blower housing 252 and the rear duct 244. This airwill channel toward the motor 246 through the passageway 270 interposedbetween the motor and its mounting housing 80. After threading its waythrough the motor, the air, then heated, will commingle with thereturned moisture-laden drying air and will be exhausted from the drierin any conventional manner. It should be understood that the bloweroutlet 274 may be connected to suitable ductwork (not shown) forselective exhaust from any part of the drier cabinet. Further, theblower may be connected to a condenser whereby the system of thisinvention may be adapted to a recirculating air type drier.

It should now be seen that an improved compact combination prime movingand air circulating drying system has been provided which is adaptableto both forced draft driers (system 68 of FIGURES 1, 2 and 3) andinduced draft driers (system 224 of FIGURES 5, 6 and 7). It should beobvious that the structural details of this arrangement could bemodified within the purview of this invention. For instance, thebulkhead utilized for supporting the combination prime moving and blowersystem could be formed or drawn to replace the mount- Of majorimportance is the fact that the motors 70 or 246 must be securelyfastened to a stationary bulkhead in the drier which is capable ofsupporting the tumbling drum at its rear wall and segregating the motorcooling air flow from the drying air as described hereinbefore. Theforegoing embodiments have been recited merely as convenient adaptationsof this invention to two of the more common clothes drying systems. Thisinvention permits a unitary prime moving and air circulating system tobe designed and built separate from the drier cabinet structure itself.The first embodiment has the advantage of combining the motor heat withthe drying air to improve the efficiency of the drier. The compactnature of this invention frees a substantial area otherwise devoted inprior art driers to the motor, blower, belts and pulleys. This addedspace may be used to reduce the size of the drier or to house certainoptional features in conjunction with a drier. This invention alsoincludes a two-stage impeller arrangement which may be selectivelyproportioned for the desired amount of air flow through both the motorfor cooling and the heaters for drying. Of inventive significance alsois the selective positioning of the motor of the second embodimentwithin the return duct adjacent the inlet to the blower housing topermit a selective adjustment of air through the motor for cooling. Withthe above and other detailed characteristics of this invention, any typedrying situation may be accommodated in a manner to maintain the motorin a cool operation condition. In addition to the advantages ofcompactness, experience has shown that the motors of this invention maybe adjusted to run cooler than motors in the conventional type driersystems which are spaced a greater distance from the heating elementsThus, the teachings of this invention have advanced the drier art in theareas of interchangeability, compactness and extended motor life.

While the embodiments of the present invention as herein disclosedconstitute preferred forms, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. A unitary prime moving and air circulating system for a clothes drierhaving a tumbling drum and a support bulkhead comprising, a motor havinga high speed shaft portion and a reduced speed shaft portion, means forconnecting said tumbling drum to said reduced speed shaft portion, saidmotor having a casing, means in said casing forming an air passagewaythrough said motor, a motor mounting housing having a flange connectedfor support to said bulkhead, an air circulating means having a dryingair inlet and an impeller connected to said high speed shaft portion,said impeller having a first and second stage, means forming anenclosure adjacent said air circulating means and connected to saidtumbling drum, said enclosure being connected to said air passagewaythrough said first impeller stage and to said drying air inlet throughsaid second impeller stage, whereby when said impeller is rotated atsaid high speed and said drum is rotated at said reduced speed, a motorcooling air flow is induced through said air passageway by said firstimpeller stage and a clothes drying air flow is forced through saidtumbling drum by said second impeller stage.

2. A unitary prime moving and air circulating system for a clothes drierhaving a tumbling drum and a support bulkhead comprising, a motor havinga high speed shaft portion and a reduced speed shaft portion, means forconnecting said tumbling drum to said reduced speed shaft portion, saidmotor having a casing, means in said casing forming an air passagewaythrough said motor, a motor mounting housing having a flange connectedfor support to said bulkhead, an air circulating means having an inletopening and an impeller connected to said high speed shaft portionthrough said opening, a conduit adjacent said air circulating means andconnected to said tumbling drum, said conduit having afirst apertureconnected to said air passageway and a second aperture to said inletopening of said air circulating means, whereby when said impeller isrotated at said high speed and said drum is rotated at said reducedspeed, a motor cooling air flow is induced through said air passagewayin one manner and a clothes drying air flow is induced through saidtumbling drum in another manner.

3. A unitary prime moving and air circulating system for a clothes drierhaving a tumbling drum and a support bulkhead comprising, a motor havinga high speed shaft portion and a reduced speed shaft portion, means forconnecting said tumbling drum to said reduced speed shaft portion, saidmotor having a casing, means in said casing forming an air passage forcooling said motor, a motor mounting housing having a flange connectedfor support to said bulkhead, an air circulating means having a heatedair inlet and an impeller connected to said high speed shaft portion,means forming an enclosure adjacent said air circulating means andconnected to said tumbling drum, said enclosure having one sectionconnected to said air passage and another section to said heated airinlet, whereby when said impeller is rotated at said high speed and saiddrum is rotated at said reduced speed, a motor cooling air flow travelsthrough said air passageway in one manner and a clothes drying air flowtravels through said tumbling drum in another manner.

4. In combination with a tumbling drum for an induced draft dryingapparatus, said drum having an air inlet and an air outlet, a primemoving and drying and cooling air circulating system comprising, a motorhaving a high speed shaft portion, a speed reduction unit drivablyconnected to said motor, and a motor cooling passageway through saidmotor having a passageway inlet connected to a source of cooling airrelatively cooler than the drying air and a passageway outlet, saidtumbling drum connected to said speed reduction unit, a blower housinghaving inlet means connected to said passageway, impeller means in saidhousing connected to said high speed shaft portion, and a ductconnecting said drum air outlet and said blower housing inlet means inseries fiow relationship, said duct having an opening therein adjacentsaid impeller for receiving at least a portion of said motor into saidduct and closely engaging said portion between said passageway inlet andsaid passageway outlet, thereby to permit cooling air flow through saidmotor cooling passageway.

5. In combination with a tumbling drum for an induced draft dryingapparatus, a prime moving and air circulating system comprising, a motorhaving means for operating a relatively high speed shaft and arelatively low speed shaft, said motor having a cooling air passagewaytherethrough, said tumbling drum connected to said reduced speed shaftfor rotation therewith, an impeller connected to said full speed shaftfor rotation therewith, and means forming a duct connecting saidtumbling drum and said impeller in series flow relationship, said ducthaving an opening therein connected to said cooling air passageway andadjacent said impeller, whereby said motor may extend into said ductthrough said opening in a manner to induce air flow through said coolingair passageway.

6. In combination, a clothes drier comprising, a tumbling drum having arecess, a drier air circulating blower adjacent said recess and in airflow relationship with said drum, a motor between said drum and saidblower and having a relatively slow speed shaft directly connected tosaid drum in said recess for rotating said drum and a relatively highspeed shaft axially in line with said slow speed shaft and connected tosaid air circulating blower for operating said blower to direct an airflow through said drum, and means including a by-pass duct through saidmotor and connected to said blower for cooling said motor duringoperation of said drier.

7. In combination, a clothes drier comprising, a tumbling drum, a driedair circulating blower in primary air flow relationship with said drum,a motor between said drum and said blower and having a relatively slowspeed shaft directly connected to said drum and a relatively high speedshaft connected to said air circulating blower, and means for coolingsaid motor during operation of said drier, said cooling means includinga secondary air flow passage through said motor and connected to saidblower.

8. A clothes drier comprising, a cabinet, a tumbling drum in saidcabinet, said drum having a perforated rear wall and a front accessopening, said front access opening being in communication with theatmosphere, said perforated rear Wall having an inwardly directedmounting housing, means for rotating said tumbling drum and forinitiating a stream of air through said tumbling drum to said frontaccess opening, said rotating means having a first speed reductionportion connected to said inwardly directed housing for rotating saiddrum and a second portion, and a two-stage impeller driven by saidsecond portion, said rotating means defining an air passage therethroughconnected to one stage of said impeller, and said cabinet having aconduit connecting said second-stage impeller and said perforated rearwall of said drum, Whereby cooling air is circulated through saidrotating means and drying air is circulated through said tumbling drumafter mixing with said cooling air.

9. A prime moving system for a drying apparatus having a tumbling drumand heating means comprising, a prime mover having a speed reductionportion and a synchronous speed portion, means for directly connectingsaid tumbling drum to said speed reduction portion for rotationtherewith, and impeller means connected to said synchronous speedportion and to said tumbling drum and said prime mover, said impellerhaving a first and second stage, said second stage being connected inseries flow relationship with said heating means and said tumbling drumto direct a stream of drying air through said tumbling drum and saidfirst stage impeller being connected in series flow relationship withsaid prime mover and said atmosphere to direct a stream of cooling airthrough said prime mover.

10. A forced draft air circulating system for a drying apparatus havinga motor and a heating means, a housing for said heating means, a motorcooling air intake duct for said motor, said housing and said ductforming therebetween an insulating air barrier conduit, said motorhaving a shaft and an air flow passageway through said motor, animpeller carried by said shaft having a first relatively small impellerportion and a second relatively large impeller portion, said firstimpeller portion being in series flow relationship with said motor airpassageway and said motor cooling air intake duct, and said secondimpeller portion being connected to said heater housing and saidinsulating air barrier passageway, and means for connecting both of saidimpeller portions to said tumbling drum, whereby the heat of said motorand said heating means are impelled in mixed fashion to said tumblingdrum.

11. A drier comprising, a tumbling drum, a heater, a motor having acooling channel and adapted to rotate said drum, a blower having anoutlet in series flow relationship with said drum, a first blower inletconnected in air flow relationship to said cooling channel and a secondblower inlet connected in air flow relationship to said heater, andimpeller means in said blower operated by said motor, said impellermeans having a first stage connected to said first blower inlet and asecond stage connected to said second blower inlet for directingpredetermined air fiows through said channel and past said heater intomixing relationship at the outlet of said blower.

12. In combination, a drier comprising, a drum, a drier air circulatingblower in primary air flow relationship with said drum, prime movermeans between said drum and said blower and having a relatively slowspeed shaft directly connected to said drum and a relatively high speedshaft connected to said air circulating blower, and means for coolingsaid prime mover means during operation of said drier, said coolingmeans including a secondary air flow passage through said prime movermeans and connected to said blower.

References Cited in the file of this patent UNITED STATES PATENTS1,935,211 Krohn Nov. 14, 1933 2,050,180 Hurxthal Aug. 4, 1936 2,589,284ONeil Mar. 18, 1952 2,736,826 Hoover Feb. 28, 1956 2,841,723 CorbettJuly 1, 1958

